1. Field of the Invention
This invention relates to a plasma display panel (PDP) and a method for driving the same. More specifically, the present invention relates to a reset waveform driving method for PDP.
2. Description of the Related Art
Flat panel displays, such as, liquid crystal displays (LCDs), field emission displays (FEDs), PDPs, and the like are actively being developed. PDPs generally have higher luminance, higher luminous efficiency and wider viewing angles than other flat panel displays. Thus, PDPs are more favorable for making large-scale screens of 40 inches or more than, for example, the conventional cathode ray tube (CRT).
A PDP is a flat panel display that uses plasma, which is generated by gas discharge, to display characters or images and includes, according to its size, more than several scores to millions of pixels arranged in a matrix pattern. A PDP may be classified as direct current (DC) type or alternating current (AC) type according to the PDP's discharge cell structure and the waveform of the driving voltage applied thereto.
A DC type PDP has electrodes exposed to a discharge space to allow a direct current (DC) to flow through the discharge space while the voltage is applied, and thus, DC type PDPs generally require a resistor to provide resistance for limiting the current. In contrast, an AC type PDP has electrodes covered with a dielectric layer, which forms a capacitance component, to limit the current and which protects the electrodes from the impact of ions during a discharge. Thus, AC type PDPs generally have longer lifetimes than DC type PDPs.
FIG. 1 is a partial perspective view of an AC type PDP. FIG. 1 shows a first glass substrate 1, parallel pairs of a scan electrode 4 and a sustain electrode 5, a dielectric layer 2 and a protective layer 3. On a second glass substrate 6, a plurality of address electrodes 8, which are covered with an insulating layer 7, are arranged. Barrier ribs 9 are formed in parallel with the address electrodes 8 on the insulating layer 7, which is interposed between the address electrodes 8. A fluorescent material 10 is formed on the surface of the insulating layer 7 and on both sides of the barrier ribs 9. The first and second glass substrates 1 and 6 are arranged in a face-to-face relationship with a discharge space 11 formed therebetween, so that the scan electrodes 4 and the sustain electrodes 5 lie in a direction perpendicular to the address electrodes 8. Discharge spaces at intersections between the address electrodes 8 and the pairs of scan electrode 4 and sustain electrode 5 form discharge cells 12.
FIG. 2 shows an arrangement of electrodes in the PDP.
Referring to FIG. 2, the PDP has a pixel matrix consisting of m×n discharge cells. In the PDP, address electrodes A1 to Am are arranged in columns and scan electrodes (Y electrodes) Y1 to Yn and sustain electrodes (X electrodes) X1 to Xn are alternately arranged in n rows. Discharge cells 12 shown in FIG. 2 correspond to the discharge cells 12 in FIG. 1.
According to the general PDP driving method, one frame is divided into a plurality of subfields, each of which is comprised of a reset period, an address period, and a sustain period.
During the reset (initialization) period, the state of wall charges from the previous sustain period are erased and the wall charges are set up in order to stably perform the next address discharge. Generally, the reset period is for preparing the optimal state of the wall charges for the addressing operation during the address period subsequent to the reset period.
The address period is for selecting turn-on cells and turn-off cells and accumulating wall charges on the turn-on cells (i.e., addressed cells). The sustain period is for performing a discharge to display an image on the addressed cells.
The reset period of the conventional driving method involves applying a ramp waveform as disclosed in U.S. Pat. No. 5,745,086. In the conventional driving method, a slowly rising or falling ramp waveform is applied to the Y electrodes to control the wall charges of each electrode during the reset period. However, the precise control of the wall charges is greatly dependent upon the slope of the ramp in the ramp waveform that is applied. Thus, in order to precisely control the wall charges, generally, a long time is required for initialization.